Human temporal bones will be collected from subjects having hearing loss and/or vertigo. They will be prepared for light microscopic study and the pathological changes will be quantified as to location and magnitude and correlated with the known functional alterations. The findings will be integrated with those of previously prepared specimens and appropriate publications will be prepared to adequately disseminate new knowledge. BIBLIOGRAPHIC REFERENCES: Schuknecht HF: Pathophysiology of endolymphatic hydrops. Archives of Oto-Rhino-Laryngology 212:253-262, 1976. McGill TJI, Schuknecht HF: Human cochlear changes in noise induced hearing loss. The Laryngoscopy 86:1293-1302, 1976.